Field of the Invention
The present invention relates to a liquid crystal display apparatus.
Description of the Background Art
An example of known liquid crystal display apparatuses includes an in-plane-switching-mode (also referred to as a transverse electric field mode) liquid crystal display apparatus in which both of two electrodes for generating an electric field that is used to drive the liquid crystal are disposed on one of two substrates that hold a liquid crystal, to thus drive the liquid crystal in a lateral (approximately horizontal direction with respect to the substrate) electric field. The liquid crystal display in the transverse electric field mode, which has a view-angle characteristic superior to a view-angle characteristic of a liquid crystal display in a twisted nematic (TN) mode, has the liquid crystal that little contributes to display. Such a liquid crystal display thus has a smaller transmittance of light than the liquid crystal display in the TN mode.
An example of liquid crystal display apparatuses in the transverse electric field mode includes a liquid crystal display apparatus in a fringe field switching (FFS) mode. This liquid crystal display apparatus has improved the above drawback. The liquid crystal display apparatus in the FFS mode is configured such that one of two electrodes that generate a transverse electric field is a latticed or comb-like electrode having slits, and is configured such that a liquid crystal is driven by a lateral fringe electric field generated between these two electrodes (strictly speaking, the fringe electric field generated in the FFS mode has a mix of a lateral electric field and a nearly-lateral electric field, but a main constituent of the fringe electric field is the lateral electric field).
An external pressure may be applied to a liquid crystal panel in the liquid crystal display in the transverse electric field mode. Such an external pressure causes a disclination (liquid crystal alignment abnormal region) to expand in an extending direction of the slits of the latticed or comb-like electrode never to return. This can produce variations in display (called “weighted traces” or “ripples”). Japanese Patent Application Laid-Open No. 2009-237236 proposes an example of techniques for solving this problem, i.e., a method of bending edges of slits of a latticed electrode.
Contrast ratio has decreased in a liquid crystal display panel that includes a latticed electrode whose slits have bent edges, as described in Japanese Patent Application Laid-Open No. 2009-237236. An increase in leakage of light at the bent edges of the slits causes this problem. Specifically, the contrast ratio decreases due to a quick rise in transmittance in a low voltage on a V-T curve (characteristic curve of voltage-transmittance) in this area.